Amplified AM/FM Antenna Wiring

[commodor47]

Our 2003 2720 SL (purchased from a private party in February, 2004) did not have a radio/CD player installed when purchased. It did have the factory installed Jensen Marine Amplified AM/FM Antenna as well as the necessary wiring terminating in the access area above the refrigerator. A few years back I installed a radio in the pre-cut slot above the refrigerator. The FM reception was poor and often non-existent. We opted to use the CD player exclusively - for several years. A few weeks ago I decided to track down the poor FM reception issue.

[FONT=&quot]Thanks to the help of Mike J. Laupp, III (mjlaupp), Dick Carver, and Moderator Bill, I was able to trace the antenna wiring in an attempt to resolve the poor reception issue. In the process I took several photos of the wiring and have posted them on:

https://photos.google.com/album/AF1Q...hRgSwjm3pFxhUg


The amplified radio antenna is a Jensen Marine AN150SR AM/FM Amplified Antenna. On our TM it is located on the back edge of the upper shell, street-side. Two wires emanate from the antenna head; one is the ground wire and the other the RF cable. The ground wire is attached to a metal strip in the back corner of the upper shell. The RF cable runs down just inside of the bag seal to a wire harness coming out of the bottom of the upper shell and is enclosed in black webbing. The webbing is looped and eventually feeds down the back of the upper shell support arm, inside a rectangular channel. Near the top of the channel, covered by the webbing, is the radio RF cable bullet connector. It is connected to an RF cable extension. The extension cable continues down the channel to a point under the TM where it enters through the floor of the lower refrigerator access area. Many other wires enter or leave the TM in this section. Also located in the channel, about 1/3 of the way down, is the red power wire for the amplified radio antenna. It is joined to another red wire by means of a bullet connector. This connector was heavily corroded and did contribute to my poor reception. I thoroughly cleaned the connector and applied a dab of dielectric grease – and made sure the connection was secure. The result was much improved FM reception. However, there was no red light visible on the antenna head. I did verify 12-volt power is present in the red wire, both below and above the bullet connector.

The Jensen web site troubleshooting guide suggested a bad ground could be one reason the red light fails to come on – and that was the next thing I worked on. The ground wire screw looked corroded and the edges of the closed loop connector had evidence of aluminum oxidation. I removed the screw, being careful not to break off the head. The existing connector was removed and new one crimped in place. The contact area was cleaned, removing all the aluminum oxide – and the ground wire was reconnected to the metal track. However, the antenna head red light did not come on.

At this point I suspect either the amplified antenna head is not working or there is a kink in the wiring, which is preventing the proper function of the antenna. Any further work will have to wait until spring. I have ordered a replacement antenna and plan on using jumpers to confirm my suspicions – and will report my findings to the board.

Dick